A child with medically intractable infantile spasms (IS) has such a poor prognosis for seizure control and for normal development that new modes of therapy are critically needed. We will study the outcome of cortical resection in these children. Children with infantile spasms have not been previously considered surgical candidates, perhaps because the seizures are classified as "generalized". This classification implies that the seizures are due to a generalized brain abnormality and therefore focal cortical resection could not be effective. The application of cortical resection to treat medically intractable infantile spasms is based on two concepts that are unique to pediatric patients. Concept 1: Since infantile spasms patients typically have generalized or multifocal, bi-hemispheric seizures, the goal of surgical assessment is not the identification of the focus of onset of seizures but rather the identification of an area of structurally abnormal cortex called the zone of cortical abnormality (ZCA). Concept 2: Resection of a zone of cortical abnormality can result in the cessation of generalized seizures, including infantile spasms. The following hypotheses will be tested: 1)CORTICAL RESECTION IS AN EFFECTIVE THERAPY IN CAREFULLY SELECTED CHILDREN WITH INFANTILE SPASMS. 2)INFANTILE SPASMS INTERFERE WITH THE DEVELOPMENTAL PROCESS. 3)ALTHOUGH INFANTILE SPASMS MAY INTERFERE WITH DEVELOPMENT, THE DELAYED DEVELOPMENT IS PARTIALLY REVERSIBLE WITHIN AS YET UNKNOWN TIME LIMITS. A randomized clinical trial (RCT) design will be used to study the outcome of "other" medical therapy (group [1]) vs. cortical resection (group [2]) in medically refractory infantile spasms patients with a ZCA. Children in group [1] who fail "other" medical therapies for a minimum of 6 months will then cross over to the surgical arm of the study. Children in group [2] who continue to have seizures after surgery will receive the "other" medical therapies protocol. The 2 groups will be compared at 6, 12 and 24 months with respect to seizure control and developmental progress (long term follow up will continue beyond the 24 months). This research will provide critical information on the effects of surgery in an intractable epilepsy of early childhood.